Purpose. To assess the effectiveness of legal management and regulation of professional participants based on the analysis of legislative, regulatory and legal documents that ensure the formation, regulation and prevention of illegal actions in the domestic stock market, as well as identify areas of cooperation with government agencies in stock market development and mediation. Methodology. In the process of research, general research methods and techniques were used, in particular: analysis and generalization to identify regulations governing the activities of professional stock market participants; analytical method to compare the effectiveness of cooperation of the National Securities and Stock Market Commission with anti-corruption organizations, synthesis to assess the completeness and effectiveness of existing legislation governing the activities of professional participants. Findings. The peculiarity of legal management and regulation of professional participants is determined; the classification mark of professional stock market participants and their activities (types of services) is formed in accordance with the National Commission on Securities and Stock Market, namely: investment firms, trade organizers (stock exchanges), clearing institutions, mortgage managers, depository institutions, companies with asset management. An analysis is performed of the effectiveness of certain laws, including the Law of Ukraine On Prevention and Counteraction to Legalization (Laundering) of Proceeds from Crime, Terrorist Financing and Financing the Proliferation of Weapons of Mass Destruction, which reduced corruption and sanctions during 20172020 and the Law of Ukraine On licensing of economic activities, which is a lever in the field of regulation and maintenance of transparency of professional market participants, prevention of illegal actions. The mechanism of cooperation of professional participants with state bodies as a component of legal management on the basis of SMIDA activity is developed. Originality. It consists in defining the areas of legal management and regulation related to the activities of professional participants in the stock market and developing mechanisms for interaction of professional participants with government agencies based on transparency, information and competitiveness. Practical value. The proposed directions of cooperation and interaction of professional participants with government agencies, in particular SMIDA and NSSMC, as part of legal management and legal support, will optimize the standards of exchange activity and development of stock trading, reduce corruption and shadowing.